Insect repellent dimethylbenzamides

ABSTRACT

This application is directed to novel compounds useful as insect repellents. The compounds of this invention have the following generic formula: ##STR1## wherein R is selected from the group consisting of hydrogen, alkyl, alkoxyalkyl, alkenyl, and cyanoalkyl; R 1  is selected from the group consisting of alkyl, alkenyl, haloalkenyl, cycloalkenyl, alkoxyalkyl, and furfuryl; R and R 1  taken together can form a ring structure selected from alkylene, alkyl substituted alkylene, alkenylene and alkyl substituted alkenylene.

This is a division, of application Ser. No. 417,306, filed Nov. 19,1973, now abandoned.

DESCRIPTION OF THE INVENTION

The compounds of this invention may be generally described as dimethylsubstituted aryl amides that are useful as insect repellents. Thecompounds of this invention have the following generic formula: ##STR2##wherein R is selected from the group consisting of hydrogen, alkyl,alkoxyalkyl, alkenyl, and cyanoalkyl; R₁ is selected from the groupconsisting of alkyl, alkenyl, haloalkenyl, cycloalkenyl, alkoxyalkyl,and furfuryl; R and R₁ taken together can form a ring structure selectedfrom alkylene, alkyl substituted alkylene, alkenylene and alkylsubstituted alkenylene.

Specific embodiments are (1) wherein R is alkenyl and R₁ is haloalkenyl,(2) wherein R is alkenyl and R₁ is alkyl, (3) wherein R and R₁ arealkenyl, (4) wherein R and R₁ are alkyl, (5) wherein R is alkyl and R₁is haloalkenyl, (6) wherein R is alkoxyalkyl and R₁ is cycloalkenyl, (7)wherein R is alkyl and R₁ is alkenyl, (8) wherein R is hydrogen and R₁is alkoxyalkyl, (9) wherein R and R₁ taken together form an alkylene oralkyl substituted alkylene and (10) wherein R and R₁ taken together forman alkenylene or alkyl substituted alkenylene.

In general, the compounds of this invention are manufactured by reactingan appropriate amine admixed with an acid acceptor, a suitable inertsolvent such as benzene or chloroform with 3,5-dimethylaryl acidchloride at reduced temperatures. The product can be separated inrelatively high purity.

In order to illustrate the merits of the present invention the followingexamples are provided.

EXAMPLE 1 N-2-chloroallyl-N-allyl-3,5-dimethylbenzamide

A solution was formed by dissolving N-allyl-2-chloroallylamine (0.032moles) in 40 ml. of benzene. Then, triethylamine (0.032 moles) was addedthereto. This solution was then cooled to 10° C. in an ice bath. Then,3,5-dimethylbenzoylchloride was diluted with 40 ml. of benzene and addedto the amine solution. The temperature rose to about 35° C. withtriethylamine hydrogen chloride separation. The next day the reactionmixture was washed two times with diluted HCl and then two times withdilute (5% solution) sodium carbonate and dried. The solvent was removedto yield 7.0 grams of product N_(D) ³⁰ 1.5367.

EXAMPLE 2 N-allyl-N-isobutyl-3,5-dimethylbenzamide

The process of Example 1 was repeated in its entirety except allylisobutylamine was used in place of the N-allyl-2-chloroallylamine. Theproduct obtained was 6.8 grams N_(D) ³⁰ 1.5130.

EXAMPLE 3 N-propyl-N-2-chloroallyl-3,5-dimethyl benzamide

The procedure in Example 1 was repeated in its entirety exceptN-propyl-N-2-chloroallylamine was used as the reactive amine to yield7.2 grams of product N_(D) ³⁰ 1.5274.

EXAMPLE 4 3,5-dimethylbenzoylhexamethyleneimine

A solution was formed containing hexamethyleneimine (0.032 moles)dissolved in 60 ml. of chloroform with triethylamine (0.035 moles) addedthereto. This solution was cooled to 5° C. in an ice bath. Then,3,5-dimethylbenzoylchloride (0.030 moles) was diluted with 20 ml. ofchloroform and added to the amine solution portion wise with mixing. Anexothermic reaction occurred and the temperature rose to 38° C. Themixture was allowed to stand at room temperature overnight and wasworked up by washing with two portions of 100 ml. of dilute hydrochloricacid and two portions of 100 ml. of a 5% solution of sodium carbonate toyield 6.1 grams of product N_(D) ³⁰ 1.5440.

EXAMPLE 5 N-isopropoxypropyl-n-cyclohexenyl-3,5-benzamide

A solution was formed containing 4.9 grams (0.025 moles) ofisopropoxypropylcyclohexylidene amine, 4.5 ml. of triethylamine in 100ml. of benzene. Thereafter, 4.2 grams (0.025 moles) of3,5-dimethylbenzoylchloride was added over a period of 30 seconds. Thetemperature rose to 35° C. After standing overnight, the mixture waswashed with 100 ml. of water, then 50 ml. of saturated sodiumbicarbonate solution, another 100 ml. of water, dried over magnesiumsulfate and evaporated in vacuo to 6.8 grams of product N_(D) ³⁰ 1.5212.

EXAMPLE 6 N-methoxyethyl-n-cyclohexenyl-3,5-dimethylbenzamide

The procedure of Example 5 was repeated in its entirety exceptmethoxyethyl cyclohexylidene amine was used as the reactive amine toyield 7.5 grams of product N_(D) ³⁰ 1.5374.

EXAMPLE 7 N-furfuryl-3,5-dimethylbenzamide

A mixture was formed containing 3.0 grams (0.03 moles) oftetrahydrofurfurylamine, 4.5 ml. triethylamine in 100 ml. benzene. Then,3.7 ml. (0.25 moles) of 3,5-dimethylbenzylchloride was added. Afterstanding for 1/2 hour, the mixture was washed with 100 ml. of water, 1normal HCl (50 ml.), 50 ml. of saturated sodium bicarbonate dried overmagnesium sulfate and evaporated in vacuo to yield 4.4 grams of productN_(D) ³⁰ 1.5366.

EXAMPLE 8 N-isopropoxypropyl-3,5-dimethylbenzamide

The procedure of Example 7 was repeated in its entirety exceptisopropoxypropylamine was used as the reactive amine. To yield 5.8 gramsof product N_(D) ³⁰ 1.5107.

The following Table is a list of compounds made in accordance withprocedures of this invention.

                                      TABLE I                                     __________________________________________________________________________     ##STR3##                                                                     Compound                                                                                                         Physical                                   Number                                                                             R              R.sub.1        Constant                                   __________________________________________________________________________     1   CH.sub.2CHCH.sub.2                                                                            ##STR4##      N.sub.D.sup.30 1.5367                       2   CH.sub.2CHCH.sub.2                                                                            ##STR5##      N.sub.D.sup.30 1.5130                       3   CH.sub.2CHCH.sub.2                                                                           (CH.sub.2).sub.3CH.sub.3                                                                     N.sub.D.sup.30 1.5136                       4                                                                            nC.sub.3 H.sub.7                                                                    ##STR6##      N.sub.D.sup.30 1.5274                                      5   CH.sub.2CHCH.sub.2                                                                           CH.sub.3       N.sub.D.sup.30 1.5329                       6   CH.sub.2CHCH.sub.2                                                                           C.sub.2 H.sub.5                                                                              N.sub.D.sup.30 1.5234                       7   CH.sub.2 CN    CH.sub.3       N.sub.D.sup.30 1.5345                       8   C.sub.2 H.sub.5                                                                              C.sub. 2 H.sub.5                                                                             N.sub.D.sup.30 1.5168                       9   CH.sub.2CHCH.sub.2                                                                           CH.sub.2CHCH.sub.2                                                                           N.sub.D.sup.30 1.5292                      10                                                                                  ##STR7##                     m.p. 56-58° C                       11                                                                                  ##STR8##                     N.sub.D.sup.30 1.5440                      12                                                                                  ##STR9##                     N.sub.D.sup.30 1.5342                      13                                                                                  ##STR10##                    m.p. 80-84° C                       14                                                                                  ##STR11##                    m.p. 50-53° C                       15                                                                                  ##STR12##                                                                                    ##STR13##     N.sub.D.sup.30 1.5212                      16   CH.sub.2CH.sub.2OCH.sub.3                                                                     ##STR14##     N.sub.D.sup.30 1.5374                      17   (CH.sub.2).sub.3OCH.sub.3                                                                     ##STR15##     N.sub.D.sup.30 1.5286                      18                                                                            nC.sub.3 H.sub.7                                                                   CH.sub.2CHCH.sub.2                                                                           N.sub.D.sup.30 1.5286                                     19   H                                                                                             ##STR16##     N.sub.D.sup.30 1.5366                      20   H                                                                                             ##STR17##     N.sub.D.sup.30 1.5107                      21   H              CH.sub.2CH.sub.2OCH.sub.3                                                                    N.sub.D.sup.30 1.5297                      __________________________________________________________________________

TESTING PROCEDURE

Each test cage consists of a tule-covered, number 116, 16 oz. waxedpaper Dixie cup with two 3/4 oz. waxed paper condiment cups stapled onopposite sides of the upper, interior perimeter. One of the cupscontains a sugar cube saturated with 0.8 ml. of acetone containing aspecific concentration of the test repellent and allowed to dry. Thesecond condiment cup contains a water-saturated cotton plug. After eachcube has been treated and allowed to dry, it is carefully weighed andplaced in the test cage. One hundred house flies of mixed sexes are thenplaced in the cages and all of the cages are placed on a 11/2 r.p.m.turntable. This procedure keeps the flies in random distribution withinthe cage and eliminates their gathering on the cage walls due to aphototropic response to outside light sources. Such gathering was foundto give a false appearance of repellency by the sugar cube. Seventy-twohours after treatment, the flies in each cage are anesthesized with CO₂,the cube is removed and reweighed and the percentage weight loss of thecube (due to consumption by the flies) is recorded. The cubes with theleast weight loss are considered to be the most repellent to the flies.A "repellency ratio" is calculated by dividing the percentage weightloss of the treated cubes by the percentage weight loss of the acetonetreated control cubes. The value of this ratio is then inverselyproportional to the repellency of the test compound and is listed in thefollowing table.

                  TABLE II                                                        ______________________________________                                        Compound   Repellency    Ratio                                                Number     1.0%          0.1%                                                 ______________________________________                                         1         0.34          0.77                                                  2         0.16          0.69                                                  3         0.20          0.69                                                  4         0.34          0.63                                                  5         0.40          0.95                                                  6         0.25          0.95                                                  7         0.87          1.1                                                   8         0.39          0.97                                                  9         0.42          0.79                                                 10         0.52          0.85                                                 11         0.51          0.97                                                 12         0.46          0.89                                                 13         0.81          0.94                                                 14         0.56          0.92                                                 15         0.23          0.49                                                 16         0.40          0.64                                                 17         0.22          0.58                                                 18         0.31          0.82                                                 19         0.89          0.96                                                 20         0.40          0.73                                                 21         0.92          1.02                                                 ______________________________________                                    

The compounds of the present invention can be used in any convenientform. Thus, the compounds can be made into emulsifiable liquids,emulsifiable concentrates, liquid, wettable powder, powders, granular orany other convenient form.

In the above description of the compounds, the following embodiments areintended for the various substituent groups: alkyl includes, unlessotherwise provided for, those members which contain from 1 to 8 carbonatoms, inclusive, in both straight and branched chain configurations;alkenyl and cycloalkenyl include unless otherwise provided for, thosemembers which contain at least one olefinic double bond and contain from2 to 6 carbon atoms, inclusive, in both straight and branched chainconfigurations; and alkylene and alkenylene includes, unless otherwiseprovided for, those members which contain from 2 to 6 carbon atoms.

What is claimed is:
 1. A compound having the formula ##STR18##
 2. Acompound having the formula ##STR19##